Spoon 1/2 cup marinara into a 13 x 9-inch casserole dish. Top with about 6 eggplant slices, 6 cheese slices and a few basil leaves. Top with 1 1/2 cups sauce and repeat layering, ending with sauce and Parmigiano Reggiano cheese.
Cover with foil and bake 20 minutes. Remove foil and bake an additional 10 to 15 minutes until surface is golden brown.